Having been a regular user of record offices for over 40 years I can report that while there are still some "black holes" the overall standard has risen dramatically. The one consistent thing is that the range of services provided and attitude to customers is enormous.
When I started researching the attitude was that no-one but "serious researchers" had any right to access the records which were basically to be preserved and preferably not looked at by the general public.(I thought I was fairly serious at the time being a history student.)
The situation now is generally that public access is the most important part of a good record office and I know several which reach very high standards of customer service where individuals go far beyond what is expected of them. The best ones have published policies on what can be expected and policies, for example, on replying to enquiries which they pride themselves on fulfilling.
All record offices have been subjected to huge cuts in staffing and resources and this is likely to continue for the foreseeable future but this does not excuse badly trained staff and unhelpful attitudes which are still to be encountered in some of the biggest and most well funded as much, if not more, than in the small and under funded.
Last year we had occasion to visit 2 large and 2 small archives which we had not visited before. The 2 smaller ones (one of which was chronically underfunded & understaffed but served a huge county)were very helpful and knew their records well. Of the larger ones, one had staff that were unhelpful in the extreme and some that were more helpful but the atmosphere was not user friendly, the other was also not user friendly although the staff were more helpful.
As in all organisations the senior managemanent are usually the ones who set the tone.
There are standards for archives, some relating to the storage of archives, and there are also awards.
If you want to complain you should first contact the archive concerned and if that gets no response try the local council which funds it and often have their own performance standards.
I don't know whether I have added anything useful to the discussion but I thought it might be useful to share these thoughts and experiences.